Conventionally, in an electrical device such as a secondary battery, a power generating element for performing charging and discharging operations is sealed in an outer or exterior package. The power generating element is formed by stacking or laminating a separator and electrodes. The separator easily shrinks when heated. When the separator shrinks, electrical short circuit occurs locally. This would reduce the output of the electrical device.
Thus, by using, as a counter measure, a separator which is formed by laminating on a heat-resistant layer of heat-resistant material a hot-melt layer having a melting point lower than the melting point of the heat-resistant layer, the separator is prevented from shrinkage or contracting even if the separator is heated. The hot-melt layers of the laminated battery are fixed together by thermal welding (see Japanese Patent Application Publication No. 2011-210524A, for example).
Incidentally, a technique is disclosed as a laminating device of an electrode and a separator, which first and second separators are drawn out in response to a rotation of a suction drum, and the electrode is bagged or pouched by the separators while the suction drum rotates once (see Japanese Patent Application Publication No. 2011-003381A). Further, another technique is disclosed in which a periphery of an electrode plate is enclosed by welding of a continuous separator so as to prevent the position of the electrode plate from being deviated (for example, see Japanese Patent Application Publication No. 2009-009919A).
However, as shown in FIGS. 14 and 15 in Japanese Patent Application Publication No. 2011-210524A, the heat-resistant layers on the outermost surface at both ends of a laminated body are respectively exposed. Also, on both end portions of each separator, the heat-resistant layer is exposed.
In such a state, there is a possibility that when the stacked battery receives a shock or undergoes vibration, the heat-resistant material of the separator may be scattered, which would reduce the electrical characteristics. In the separator shown in FIG. 3 of Japanese Patent Application Publication No. 2011-210524A, since a hot-melt layer is disposed on both surfaces of the heat-resistant layer, the heat-resistant material is not scattered. However, the layer thickness of the separator becomes thicker.
Further, in any of Japanese Patent Application Publication No. 2011-003381A and Japanese Patent Application Publication No. 2009-009919A, when transporting or conveying the separator formed by laminating the heat-resistant material and the hot-melt material, no specific consideration is given so as block the otherwise easy to be scattered heat-resistant material from being scattered easily.
In this configuration, when using a separator which is formed by laminating the heat-resistant material and the melt material there is a possibility that the heat-resistant material of the separator may be scattered in the separator welding apparatus.